The interdental brushes generally known and used consist of a handle and a brush body formed of a thin metal wire strand folded and twisted wherein a filament is captured between the wire. The brushes are generally cylindrical or cone-shaped and the handle is generally synthetic and often cylindrical of appropriate size to hold in the hand. A wire base of the brush body is often fixed onto the handle using methods such as insert molding and other physical joining methods including thermal fusion by high frequent and ultrasonic waves to integrate the brush body with the handle.
The problem with such conventional interdental brushes is that the base was often bent to fit into the gap between teeth to insure the best angle between the handle member and the brush. Repeating this procedure will damage the wire quite easily in a fairly short time period.
As a proposed solution, some interdental brushes have a handle, and a brush support member to fix and hold the brush body, with the tip of the handle branched in two on which the brush support member is pivotally supported in a freely rotating manner. (See Kokai Disclosure No. 9-121942 (Patent Document 1). However, such interdental brushes have the problem of increased manufacturing costs due to the increased number of parts necessary to make the brush support member.
Another type of interdental brush has been proposed in which the handle is made of two sub-handles, right and left sub-handles symmetrically centered on a common axis to form one handle, with the tip of both sub-handles fixed via five rings with a wire support. (See Kokai Application No. 8-508179 (Patent Document 2).
The interdental brush shown in Patent Document 2 adjusts the angle of the brush body against the handle by sliding the right and left sub-handles in the direction of the handle by which operation the cleaning action is enhanced. By forming the handle member so that these two sub-handles can open at an angle of 180°, the handle can be formed in one process whereby the number of parts and costs incurred are reduced.
Patent Document 1: Kokai Disclosure No. 9-121942
Patent Document 2: Kokai Application No. 8-508179